Such automats are exposed to intentional interference and material damage, which can be vandalism or can arise due to manipulations with the attempt to obtain the service of the automat without previous insertion of coins or to seize coins previously dropped in by third parties or even coins already collected by the automat. Thus, a foreign body, especially, for example, a folded piece of paper, is pushed into the coin channel, which piece of paper, when third parties thereafter drop in coins, is ever further pushed along in the coin channel. Also, attempts are made initially to force the foreign body maximally far into the coin channel by means of a wire, a thin, elastic saw blade or another auxiliary means, so that many coins can accumulate. Later on, the attempt is then made to fish the coins out of the coin channel with the aid of such auxiliary means. Also, by introducing such auxiliary means, attempts are made to interfere with the coin checker and/or its control device, with the intent to effect issuance of coins stored in the automat. Such manipulations are to the disadvantage of the entity interested in the performance of the automats, lead to operating disturbances of the automat which must be remedied by servicing personnel, and--if auxiliary means are used for manipulations--lead to damages with the consequence of expensive repairs. As compared with the thus-caused expenses, loss by coins obtained through misuse normally is less significant, but even this loss can be appreciable, if attempts at emptying one or even several coin vaults are successful.